The Louis Garneau Mesh Carbon Short Sleeve Base Layer is the short sleeved version of their Mesh Carbon Sleeveless Baselayer. And perhaps, with the addition of the sleeves, it's a bit more suited to variable weather conditions. It's still superlight like the sleeveless baselayer, and its Carbon Ion Mesh is half the fabric weight of most jerseys. It's a perfect layer for those mornings when you might grab a pair of armwarmers to get started. And you won't have an annoying cold strip at the top of your arm, as it will cover that gap at the shoulders under your team jersey unlike a sleeveless baselayer. As you ride and the mercury starts up, unzip your jersey and the superlight mesh will allow maximum airflow to keep you at the right temperature. The textured interior of the mesh fabric has excellent wicking properties to keep your skin dry and comfortable.